On 2/6/07, Praveen Kumar <rptechie@xxxxxxxxx> wrote:
Pharaoh . wrote:I am working on things which requires lot of data to be sent to the module continuously.I am not sure if what we are trying to do now will be of help to you. But it still comes under the broader "Accessing a file from kernel space" :-)
Yes, an aquisition system. The real work has not started yet, I was just trying to figure out
how to go about it.
We are considering two approaches for our work -
1. Follow the loop approach - Where the file is mapped into the memory & the IO is done. Please go through the loop device code, for more precise understanding.
If that is not what you are looking at then we are using a less optimal approach, which is but a TEMP HACK.
2. use the filp_open and stuff.
Personally I would not suggest 2nd approach, as we are facing glorious problems with it. So we are looking to change our design towards the 1st approach.
If you have any other ideas plz ping back bcoz even we are on a look out for optimized io to/fro file from kernel space.
Regards
Rp
On 2/2/07, Jon Masters <jonathan@xxxxxxxxxxxxxx> wrote:Pharaoh . wrote:
> I know that this should be avoided as much as possibleI know this must
> have been discussed here many times before, and I know the various ways
> I can read a file from my module. But I am not very sure what is the
> best way to do so. Let me list out my approaches ranging from very crude
> to standard ones which we read in books.
> 3. Using sysfs.
It'd be best to know what you're trying to do. But generally, pushing to
the kernel from userspace (yeah, I know, twice the fun) is better than
even remotely thinking about using sys_* from in-kernel. Rule is:
* If you're using sys_<insert function here>, it's wrong.
But tell us more about what you're trying to do. Do you just need a
userspace library to parse some config data and shove it into the kernel
or do you need a high performance, high throughput data stream for some
highly reliable hardware acquisition system?
Jon.
>We are considering two approaches for our work -
> 1. Follow the loop approach - Where the file is mapped into the memory & the IO is >done. Please go through the loop device code, for more precise understanding.
Praveen,
Can you explain the loop method in detail? Is this related to mapping the device memory in process address space i.e. mmap?
